Kenneth s



K. S. GUITERMAN., ELECTROLYTIC PROCESS FOR THE EXTRACTION 0F COBALT OXIDS.

, APPLICATION FILED AIJG26, 19I5. mman.

351g Latte/ww entran sacarse rarest onirica KENNETH S. GUITERMN, 0F NEW YORK, N.

- ELECTBOLYTIC PROCESS 'FOR THE EXTRACTIQN F COBALT OXIDS.

To all wzom t may concern: Y

Be it known that I, KENNETH S. Guirau- MAN, a citizen. of the United States, and

'-the VsolutionV containingthe Vcobalt-fwhich usually exists .as a sulfate or as a chlorid, with an oxidizing agenty such as bleaching powder to convert the sulfate into an oxid or a hydrated oXid. The solutions, however, are usually impure due to the presence of nickel salts, such as nickelsulfate. When the bleaching-powder is addedito such an `Vimpuresolution, its action is selective in that itftends t"precipitateitlrstkan oXid or hydrated oXid of cobalt and thenVY a salt'ofnickel is thrown down from the solution. As a resultof this fractional precipatory action of the bleaching powder, it .is obvious thatit is impossible to remove all or even the '-1najor portion of the cobalt from the soluolti'onwitlioutatrvtheasame timerprecipitating someof the nickel'. In order;"tlierefo1'e to finally obtain a pure oXid of cobalt it has been necessary to repeat the operation of fractional precipitation until the quaint-ity of nickel which finally remains with Athe cobalt is of negligible amount. These manifold operations involve many troublesome delays together with the formation of objectionable intermediate by-products carrylng varying amounts of cobalt and nickel 'which must be re-handled during sometadrated oxid. in such a manner as to render it Specification of Letters Patent.

Patented Aug@ 221, wi

` ap'pii'auoa niet .augustaaigia serial no. 47,427.

freeA from the objectionable features above Suggested and at the same time to recover.

in one operation, substantially all. of the cobalt in an essentially pure condition free from nickel.

A further object is' to obtain oXid or hydrated oXid of cobalt in a substantially pure condition at a very low cost and by a y process which is continuous and practically automatic.

In the electrolytic process and as a result of the passage or" the electric` current through the solution or electrolyte-which rimtains not only cobalt and nickel salts but usually'aV certain amount of soluble chlorids,

such as commonly salt (NaCl), there is liberated at the anode nascent chlorin gas, which has a tendency to rise to the surface ande escape into the atmosphere. This chlorin gas is the essential element in the conversion of the soluble cobalt to the oXid or hydrated oXid of cobalt. The action ofthe chlorin in accomplishing this result may be briefly summarized as follows: l. Reaction of the ehlorin gas with the electrolyte to form a hypochlorite. 2. Reaction of the hypo? lchlorite with the solution of cobalt to form the hydrated oxid of cobalt (a brownish black precipitate) and some free hydrochloric or sulfuric acid. Y In view of the i'act that hydrated oXid 'of cobalt, is extremely soluble in even weak acids7 it is necessaryin this process to provide for the neutralization of any free acids stormed in the second reaction defined, in order that the precipitation of the cobalt may proceed in an efficient manner. Such neutralization is accomplished through the continuous addition to the electrolyte of a basic neutralizing` agent such as sodium carbonate during the progress of the electrolysis.

From the above general outline it is obvious that the el'iciency of the process will depend upon. two factors, namely: c. The formation of the maximum amount` of hypochlorite possible. The correct neutralization of the free acids formed through the precipitation of the cobalt' oxid. In general it may be stated that the amount of -hypochlorite which can be formed in a solution of this character will be directly in proportion to the amount of gaseous chlorin held in the solution. rllhe eliiciency ol the l speed sufficient to retain the retaining this gaseous Ychlorin is that its release would also` be highly objectionable owing to its injurious ei'l'ect upon the lungs of workmen in the vicinity. I attain this latter object broadly by causing the electro- .lytic solution to pass across the electrodes in a continuous stream, in a direction and at a chlorin gas in the solution. Preferably the solutionis fed in at the top of an electrolytic vat andthe precipitates withdrawn from the bottom of the vat in a continuous stream.

By means oit' my process also, the hydrated oxid of cobalt is removed from the electrolytic vat in a continuous manner, thereby preventing the accumulation of the oXid at the bottom of the electrodes which would tend to shortcircuit the system, Furthermore, as a result of the directional flow of the electrolyte7 the oxid of cobalt is prevented from adhering to the anode and finally causing a short circuit between' the anode and the adjacent cathode. This procmay be carried out in any suitable electrolytic apparatus by arranging thf-l streams of the electrolyte in such a manner that they cause adownwardly directed current across the anode electrodes at the proper speed.

In the accompanying' drawings is shown one form of apparatusI which may be utilized to carry out the process.

ln the drawings: Figure ,t is a center vertical .section of an electrolytic vat taken in a plane parallel to the electrmle plates; and Fig. 2 is a side elevation partly in section of the vat lshown in` Fig. l and at right angles to4 this ligure.

In cai-.rying out my improved process the terminal plates or electrodes are arranged parallel to each other in a suitable retaining vessel or vat with an inlet for a continuous supply of electrolytic solution directed between the members of each pair of electrodes. The electrolyte flows in a practically continuous stream from the inlets and passes between and'in contact with the electrodes so that the entire surface of each electrode or at least the anode electrode is subjected to the action of the continuously passing current. The velocity of the stream may be controlled in any desired manner and is always sullicient t o retard if not to prevent entirely thev rising of the liberated chlorin gas. Preferably, the direction of flow is substantially downward and transverse to the face of the electrodes and the best results are attained when the flow is vertically across the electrodes.

Preferably the outlet is located at a point below the bottom of the electrodes so that the flow of electrolyte will be in approximately the same path as the naturally falling precipitates. The precipitates of cobalt oxid may be separated from the withdrawn solutions in any suitable manner, as by liltering or by depositing the same in suitable settling boxes, or the .entire electrolyte, carrying thesuspended oXids, may be returned to the electrolytic vat and the operation'repeated.

In the particular apparatus shown in` the accompanying drawings, the vat 4L may be of rectangular section provided with a hop- .per bottom 5 having an outlet (i at its lowest point. Plate electrodes 7 are suspended in the upper portion of the vat by straps 8 depending from cross-bars 9 resting on the main bus bars 10. Supply pipes ll, communicating with the source of supply of thev solution, are led along each side of the vat and have a plurality of discharge outlets 12 projecting down into the vat. orilices of these outlets are pointed in a genh eral downward direction toward the outlet (5. The electrolyte is drawn out through the outlet by any suitable means, such as a pump, at'substantially the same rate as it is fed to the vat through the various supply pipes and therefore there is at all times a generally downward current of electrolyte serving to prevent the chlorin gas from :rising through the solution and escaping. The speed of this on` the quantity of electrolyte supplied'to a given size tank through the oriiices, and drawn from the tank through the outlet. I have found that with a tank having a capacity of about 2l() may be obtained by feeding the solutions thereto and drawing` the out-flowing stream therefrom at the rate of from 40 to S0 gallons per munite.

In the foregoing description of the ess it is stated that a. basic neutralizing agent, such as sodium carbonate, is added with the cobalt solution to the electrolytic vat and is present during the electrolysis.

As the object of this agent is to neutralize any vtree acid which might dissolve the cobalt oxids formed1 it is obvious that the flow past the electrodes and the handling of the oxids may be carried on so rapidly that the small amounts of acid formed are prevented from acquiring a concentration which might dissolve the cobalt oxids. Due to the activity with which sodium carbonte precipitates cobalt from .its solution, it is preferable to add the neutralizing re-agent after The current will of course depend 105 gallons, good results 110 the solution has passed the electrodes and after the, oxids have formed. In one Sucycessful -working of the process the base is added to the flow after it has passed from the electrolytic vat.

g I-Iaving thus described my invention, I

claim:

l. In the art of obtaining cobalt oxids from a solution containing a Soluble cobalt salt, the process which consists inl subjecting the solution to an-electrolytic laction in the presence of a soluble chlorid, passing the solution'in a doivngggardly directioned current Vat a speed perinltting ithe retention of the chlorin gas liberated in the solution -tlicrcbyto form a hypochlorite and 'permitting the hypochlorite so formed to react on the solution 'of cobalt in the presence. of an agent capable of preventing tlie formation ot any free acid in the solution.

' 2. In the art of electrolytically extracting cobalt oxids from solutions containing a soluble chlorid and soluble cobalt salt, the

processwvliich consists in causing a current of the elcctrolytic solution to pass across the anode electrode in a direction and velocity to retain in the solution any rhlorin gas generated adjacent the electrode by the electrolytic treatment of the solution.

3. In the art of electrolytically extracting cobalt oxids from solutions containing a soluble cobalt salt, the process which consists in subjecting the solution to an electrolytic action in the presence of a coacting clilorin-forming-agent and causing all of the frcc chlorin so foi-ined to reactvchemically upon the solution.

4. In the art of electrolytically extracting. cobalt oxids from' solutions containing a cobalt salt and a soluble chlorid, the process which consists in directing the solution do\vn\\'ardly past the anode electrode and in the presenceV ot lan agent, designed to neutralize any acid which may be formed adjacent the anode.

5. In the art of forming cobalt oxids from solution containing cobalt and nickel salts, the process 4which consists in subjecting the solution to an clectrolytic action in the pres, lence of a,basicv neutralizing agent and in th salt, the process Jwhich consists in subjcting the'solution to the action of ahy ochlorite in the resence of a'n agent capa le of preventing t e formation of any solvent of the cobalt oxid formed.

8. The improvement in the art of forming cobalt oxids, which consists in subjecting a solution containing a soluble cobalt salt, a

soluble chlorid and a neutralizing agent to an electrolytic action, the neutralizing agent being 'addedata rabijust sufficient to maintain a neutral orasubstantially neutral condition inthe solution.

i 9. vIn the art of forming cobalt oxids from solution of cobalt salts, theprocess which consists in subjecting the solution to the action of free chlorin in the presence of a y neutralizing agent.

from solutions containing cobalt salts, 'the Y process which consists in subjecting the solution to an electrolytic action in the presence ci an agent which will react therewith to form a. free acid and automatically'removin the acid incidentally formed at a rate whic process which consists in subjecting the soin,"

tion to an electrolytic action and automati-l cally removing the acid incidentally formed at a rate which will prevent its accumula-.-

tion and consequent concentration.

Signed at New York, in the county of fl: New York, and State of New York, this 17 v day of AugustA. 13.1915. v,

KENNETH l 10. In the 4art of extracting cobalt oxids 

